Society of Photo-optical Instrumentation Engineers, Proceedings of SPIE
DOI: 10.1117/12.389400
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We have developed a highly integrated liquid-crystal-on-silicon light valve for three-panel color projector. The silicon panel was designed and fabricated by a 0.35 micrometers, 3-metal and dual-voltage CMOS process with a spatial resolution of 1280 x 1024 pixels. The pixel pitch was 12 micrometers, the fill factor was 90% and the display area was 0.77" in diagonal. Eight-bit digital data drivers and gamma-correction circuitry were integrated into the silicon panel for true gray scale and full color representation. The display panel was assembled with a mixed twisted nematic and birefringence liquid crystal cell for high contract at CMOS compatible voltage. Contrast ratio was typically 200:1 at 5.5Vrms. In addition, silicon surface layers, liquid crystal materials, pixel structures and driving schemes were carefully optimized for the minimization of visual flicker. Flicker ratio of less than 3% was achieved at 60Hz frame rate. The optical sub-system utilized a trichroic prism assembly for both color separation and recombination. With this trichroic prism assembly incorporating three silicon light valves, a compact and high-contrast SXGA video projector was demonstrated.